In this proposal we first document our commitment and enthusiastic endorsement for the concept of the Cooperative Multi-Center Network of NICUs. This network would provide a unique opportunity to definitively establish the safety and efficacy of various treatment modalities as well as plan management strategies for NICUs. We then delineate and describe our personnel, facilities, patient population, data base and clinical research accomplishments. Each year our state certified, Level III unit admits about 750 complicated patients, including 54% inborn. The staff of 9 fulltime neonatologists are complemented by a broad array of pediatric subspecialists, with whom we have accomplished productive clinical research. They are ably supported by excellent nurses, respiratory therapists, bio-engineers, ultrasonographers and other medical technicians. Patient care is facilitated by extensive clinical and research laboratories as well as outstanding specialized radiology services. We have a preeminent follow-up program that has enrolled over 90% of 1034 infants less than 1500 g for the past decade providing an extensive data base. There is a firm institutional and departmental commitment to this cooperative project. The neonatal staff are dedicated to active participation in both study design and implementation. Computer facilities are available to store, manage and transfer the voluminous data which will be generated. The problem of neutropenia and the role of granulocyte transfusions in its management has been selected as the proposed protocol to be conducted by the network. Neonatal sepsis, complicated by neutropenia, is a common problem which carries a high mortality and morbidity. Preliminary reports have suggested that granulocyte transfusions may reduce the mortality rate for septic, neutropenic neonates, nonetheless our data did not confirm this. However, to complete a prospective randomized sequential trial requires almost 250 patients, obviously an impossible number for a single unit to study within a reasonable period of time, but ideally suited to the network. With 8 centers in the network a definitive study on the role of granulocytes in neonatal sepsis could be completed in 24 to 30 months. In summary, we have the personnel, patients, support programs and, above all, the firm institutional and staff commitment necessary to ensure successful participation in this project.